Temporary seal for oil spill seems to be holding

WASHINGTON — A top BP official said the team working on its runaway oil well was encouraged Friday morning that a temporary seal will continue to keep oil from its deadly gush into the Gulf of Mexico even as they work to complete a permanent relief well.

President Barack Obama called it "good news" but cautioned "that we don't get ahead of ourselves here."

"You know, one of the problems with having this camera down there is that when the oil stops gushing, everybody feels like we're done, and we're not."

He said everyone has "taken hope in the image of clean water instead of oil spewing in the Gulf," but added that they were proceeding cautiously and with the understanding that the prudent course of action might still be to capture the oil until thje relief well is drilled.

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"Either we will be able to use it to stop the flow or we will be able to use it to capture almost all of the oil until the relief well is done. But we're not going to know for certain which approach makes sense until additional data is in," he said.

A day after BP stopped the flow of oil and gas for the first time since the Deepwater Horizon rig exploded in April, the results of a well integrity test are promising, said Kent Wells, a senior BP official.

Among the company's concerns: that additional pressure on the new seal would force oil and gas to leak out of weak spots in the well, deep below the floor of the ocean. But the current monitoring shows no negative evidence of breaching, Wells said Friday morning in a briefing with reporters.

Sonar tests by remotely operated vehicles also were unable to identify breaching elsewhere, Wells said. The company will run additional seismic tests today to look for breaches far below the sea floor, deep into the lower geological formations the well punches through to reach the reservoir of underground oil and gas.

That seismic information will be valuable as they move forward with the relief wells that will permanently close off the runaway well, said Wells. Work on the relief well resumed today; the company is in the delicate final stages of drilling to the existing well, he said.

BP and government officials remain uncertain whether, once their tests are complete, they'll keep the seal closed.

The 75-ton piece of equipment that's capping the well wasn't designed to permanently seal it - only a relief well will permanently cut of the flow of oil and gas that has fouled the Gulf of Mexico.

Instead, it was designed to capture almost all of the oil flowing from the well and to send it to four processing ships on the surface of the ocean until the relief well was drilled.

Those vessels would have the capacity to capture as much as 80,000 barrels a day. And the cap only would have been used to seal the well if a hurricane forced the processing ships to flee the path of the storm.

However, if the well passes the pressure test, they could keep it in place until the relief wells permanently plug the original well.

Drilling experts are using the ongoing integrity tests to determine whether pressure can be maintained without an effect on the wellbore and its casing. If pressure drops, that signals there's a potential weakness in the well and that oil and gas could be escaping elsewhere.

Friday morning, the pressure was at 6700 psi and steadily building, Wells said. They knew that if the pressure didn't reach 6,000 psi, the well lacks integrity and oil and gas could be flowing out somewhere along the length of the pipe. They also know that if the pressure is above 8,000 psi, the well has complete integrity, Wells said.

Between ranges, however, "that's where the detailed analysis has to take place and that's what has to go on today," he said.